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# BlendTreeInvalidNode

A blend tree node that’s internal only or sources from an invalid
definition.

```
struct BlendTreeInvalidNode
```

## Overview

This structure adopts [`BlendTreeNode`](/documentation/RealityKit/BlendTreeNode) and adds the ability to detect a
node that contains neither an animation nor any branches in the blend tree.

You don’t create instances of this structure. Instead, detect whether your
blend-tree node matches the framework’s criteria for invalid nodes by
checking the node type, as the following code demonstrates.

```swift
// Get the blend tree's root node.
guard let blendNode = blendTree.root as? BlendTreeBlendNode else { return }
for node in blendNode.sources {
    if let invalidNode = node as? BlendTreeInvalidNode {
        // Respond to invalid-node criteria.
```

## Topics

### Configuring the blend tree invalid node

[`var name: String`](/documentation/RealityKit/BlendTreeInvalidNode/name)

A textual name for the blend node.

[`var weight: BlendWeight`](/documentation/RealityKit/BlendTreeInvalidNode/weight)

The amount that an animation impacts the entity it applies to.

## Relationships

### Conforms To

[`BlendTreeNode`](/documentation/RealityKit/BlendTreeNode)

---

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